Old saws on aspen? Additional 2 stroke oil..?

[michael_cullum]

First off apologies as aspen questions have probably been done to death, however...

 

Recently switched over to using aspen for the benefit of our equipment, sick of perished fuel lines, carb diaphragms, varnished carbs in things that aren't used often etc etc, all the usual reasons.

 

However we run a couple of old Jonsered saws, which are intended for 40:1 mix, what would you people do in this instance? As it happens they're the ones that are likely to see the biggest benefit from the aspen as they're the big old dinosaurs that don't come out too often... Has anyone tried topping up aspen to a more oil rich ratio? To my mind this would still mean you have the benefits of the alkylate petrol and can use it in older machines? Or is the stuff totally incompatible with 2SO?

 

 

[Stubby]

1 hour ago, michael_cullum said:

First off apologies as aspen questions have probably been done to death, however...

 

Recently switched over to using aspen for the benefit of our equipment, sick of perished fuel lines, carb diaphragms, varnished carbs in things that aren't used often etc etc, all the usual reasons.

 

However we run a couple of old Jonsered saws, which are intended for 40:1 mix, what would you people do in this instance? As it happens they're the ones that are likely to see the biggest benefit from the aspen as they're the big old dinosaurs that don't come out too often... Has anyone tried topping up aspen to a more oil rich ratio? To my mind this would still mean you have the benefits of the alkylate petrol and can use it in older machines? Or is the stuff totally incompatible with 2SO?

 

 

I would say provided you have changed all the rubber components that will have been attacked by the pump fuel over time , then they would be fine . I do however mix Aspen4 with Redline 2t oil at a ratio of 50:1 so it can be done .

[nepia]

Was that 40:1 mix stipulation made when most saws ran on 25:1?  The old 25:1 is nowadays 50:1 due to improvements in the oils and engines and that is presumably therefore what Aspen allows for.  Your modern equivalent mix would be 80:1.

 

All supposition on my part but worth thinking about perhaps.

[peatff]

My old Dynamac DY41 was 25:1 but it has run happily on Aspen2 with no additional oil and the added benefit of less smoke.

[michael_cullum]

Perhaps I'm worrying needlessly! Just I would hate to burn up a piston or barrel on one of the old ones, as they're likely to be pretty hard to replace!

[Heavy Oil Saw]

From what I’ve gleaned from old saw restoration vidyas and the likes, modern 2SO alleviates the need for ratios in old saws. So a 25:1 mix old saw will run 50:1 on modern mix (Stihl Motomix, Aspen 2). I didn’t believe it at first, but heard/read from many sources, so I believe it true.
If you don’t think it’ll work, run Aspen 4 stroke and mix to ratio as mentioned above. I was contemplating this method for a run in period of 40:1 for a saw I’m building (use the 4 for your mower as well).

[Stere]

So all old 25:1 can be swtiched to 50:1? (Both with regular 2 stroke oil or just aspen?)

 

Would save alot of bother as atm have 3 fuel can mixes one 25:1 one 40:1 and and one 50:1. As the first two don't get used often proabaly fuels going stale etc....

 

Cheapo chinese saws still spec 25:1.....

Edited March 4, 2020 by Stere

[felixthelogchopper]

I have run a Spud ported Husky 181 SE for a few years now on standard Aspen 2t with no problems and several benefits.

[Stere]

How bout a 050 AV though or a old mculloch job?

[felixthelogchopper]

As I understand it, the old ratios were to do with the quality of the oil rather than the saw.